NORMAN — A worker who fell from a construction site at the University of Oklahoma died of his injuries Monday, the worker's company confirmed.

Work continues on Headington Hall on the campus of the University of Oklahoma in Norman. Photo by Steve Sisney, The Oklahoman

Jimmy Guthrie, president of Universal Roofing and Sheet Metal, said the worker was taken by helicopter to a hospital after the incident, where he later died.

The worker, whose name was not released, fell from OU's Headington Hall at 9:15 a.m. Monday, said Dana Birkes, a spokeswoman for Flintco, the construction firm working on the building. After the man fell, other workers administered first aid and called 911, Birkes said.

The U.S. Department of Labor's Occupational Safety and Health Administration is investigating the incident, spokeswoman Elizabeth Todd said.

Birkes said it appears the worker hadn't been properly secured to the building.

Flintco's safety policy requires workers to wear safety harnesses that are fastened to tie-off points on the building, Birkes said.

OU officials referred questions about the incident to Flintco, saying buildings under construction are the property of the contractor.

Headington Hall, the university's new athletic dormitory, is expected to open before the 2013 fall semester.

The incident comes just weeks after an OU student fell to her death from another campus building. Casey Cooke, 22, died after falling from Evans Hall in the early hours of June 3.